Previous prospective studies have shown inconsistent associations between serum 25-hydroxyvitamin D [25(OH)D] level and lung cancer incidence. The aim of the present study was to explore the associations of serum 25(OH)D levels with incidence of lung cancer overall and different histologic types. We performed a population-based prospective case-cohort study including 696 incident lung cancer cases and 5804 individuals in a subcohort who participated in the second survey of the Nord-Trøndelag Health Study in Norway. Cox proportional hazards regression models counting for the case-cohort design were used to estimate hazard ratios (HRs) with 95% confidence interval (CIs) for lung cancer overall or histologic types in relation to serum 25(OH)D levels. Compared with the fourth season-specific quartile of 25(OH)D (median 68.0 nmol/L), lower 25(OH)D levels were not associated with the incidence of overall, small or squamous cell lung cancer. However, the risk of adenocarcinoma was lower in the second and third quartiles (median 39.9 and 51.5 nmol/L) compared with the fourth quartile, with HRs of 0.63 (95% CI 0.41-0.98) and 0.58 (0.38-0.88), respectively. The associations of lower levels of 25(OH)D with a reduced risk of adenocarcinoma were only observed in the overweight/obese subjects [HRs for second and third quartiles: 0.40 (0.22-0.72) and 0.50 (0.27-0.92)] but not in the normal weight subjects [HRs: 0.95 (0.52-1.75) and 0.60 (0.32-1.10)]. Serum 25(OH)D levels were not associated with the risk of lung cancer in general. The observation that lower 25(OH)D levels were associated with a lower risk of adenocarcinoma should be interpreted with caution.

The aim of this study was to determine the prevalence of self-reported chronic idiopathic pain among adolescents in relation to age and gender, and to explore how pain interferes with daily activities. The study was performed in Nord-Trøndelag County, Norway in 2006-2008. All adolescents were invited to participate; the response rate was 78%. Participants completed a comprehensive questionnaire, including questions about pain and interference with everyday life. Chronic idiopathic pain was defined as pain at least once a week during the last 3months, not related to any known disease or injury. The final study population, with complete pain questionnaires, consisted of 7373 adolescents aged 13-18years. Chronic pain was reported by 44.4% of the participants, and 25.5% reported pain in at least 2 locations. Chronic idiopathic musculoskeletal pain was most prevalent (33.4%), and the neck/shoulder was most commonly affected. Musculoskeletal pain in 3 or more locations was reported by 8.5%. Pain almost daily was reported by 10.2%. More girls than boys reported pain. In girls, the prevalence of pain increased with age. A high number of pain-associated disabilities were reported, and 58.5% described difficulties doing daily activities in leisure time. Subjective disabilities were higher in girls, and increased with the frequency of pain and the number of pain locations, as shown by high disability in adolescents with musculoskeletal pain in 3 or more locations. Chronic idiopathic pain, especially multisite pain, is common among adolescents, and those suffering from it report a major impact on several areas of daily living.

Chronic obstructive pulmonary disease (COPD), low lung function independent of diagnosis and markers of inflammation are all associated with increased morbidity and mortality. Microalbuminuria, reflecting endothelial dysfunction, could be a relevant inflammatory marker of potential systemic effects of COPD. We hypothesised that there was a positive association between microalbuminuria and mortality in individuals with COPD. We conducted a 12-year follow-up study of 3129 participants in the second survey of the Nord-Trøndelag Health Study (HUNT), Norway. At baseline, albuminuria was analysed in three urine samples and spirometry was performed. Among the participants, 136 had COPD and microalbuminuria, defined as a urinary albumin/creatinine ratio between 2.5 and 30.0 mg·mmol(-1). The main outcome measures were hazard ratio of all-cause mortality according to microalbuminuria. Compared to those with COPD without microalbuminuria, the adjusted hazard ratio for all-cause mortality in those with COPD and microalbuminuria was 1.54, 95% CI 1.16-2.04. This result was similar after excluding cardiovascular disease at baseline. Classifying COPD severity by Global Initiative for Chronic Obstructive Lung Disease, there was a positive association trend with increasing severity stages. Microalbuminuria is associated with all-cause mortality in individuals with COPD and could be a relevant tool in identification of patients with poor prognosis.

The objective of this study was to examine the association of maternal and paternal height with pregnancy length, and with the risk of pre- and post-term birth. In addition we aimed to study whether cardiovascular risk factors could explain possible associations.

Parents who participated in the Nord-Trøndelag Health Study (HUNT 2; 1995-1997) were linked to offspring data from the Medical Birth Registry of Norway (1997-2005). The main analyses included 3497 women who had delivered 5010 children, and 2005 men who had fathered 2798 pregnancies. All births took place after parental participation in HUNT 2. Linear regression was used to estimate crude and adjusted differences in pregnancy length according to parental heights. Logistic regression was used to estimate crude and adjusted associations of parental heights with the risk of pre- and post-term births.

We found a gradual increase in pregnancy length by increasing maternal height, and the association was essentially unchanged after adjustment for maternal cardiovascular risk factors, parental age, offspring sex, parity, and socioeconomic measures. When estimated date of delivery was based on ultrasound, the difference between mothers in the lower height quintile (

The aim of this study was to assess the association of chronic pain with different lifestyle factors and psychological symptoms in a large, unselected adolescent population. Pain was evaluated as chronic non-specific pain, chronic multisite pain, and in additional analyses, chronic pain with high disability. The study was performed during 2006 to 2008 in Nord-Tr?ndelag County, Norway. Adolescents aged 13 to 18 years were invited to participate. The response rate was 78%. The final study population consisted of 7,373. Sedentary behavior and pain were associated only in girls. In both sexes, overweight and obesity were associated with increased odds of pain. Whereas both smoking and alcohol intoxication showed strong associations with pain, the associations were attenuated after adjustments for psychosocial factors. Symptoms of anxiety and depression showed the strongest associations with pain (odds ratio 4.1 in girls and 3.7 in boys). The odds of pain increased gradually by number of unfavorable lifestyle factors reported. This study revealed consistent associations between lifestyle factors, anxiety and depression, and chronic pain, including multisite pain and pain with high disability. The consistency across the different pain categories suggests common underlying explanatory mechanisms, and despite the cross-sectional design, the study indicates several modifiable targets in the management of adolescent chronic pain.

This study showed a clear and consistent relation between different lifestyle factors, anxiety and depression, and the pain categories chronic non-specific pain, multisite pain, and also pain with high disability. Independent of causality, it underlines the importance of a broad perspective when studying, preventing, and treating chronic pain in adolescents.

It has been suggested that paternal genes may contribute to the risk of maternal hypertensive disorders in pregnancy and that genes associated with cardiovascular disease could be involved in the etiology of maternal hypertensive disorders in pregnancy. If these genes are of fetal origin, one would expect that paternal cardiovascular risk factors are associated with the fathering of pregnancies in which the mothers experience hypertensive disorders. Thus, we have studied 14,130 offspring and parents in Norway (1967-1997) to assess whether the fathering of pregnancies complicated by hypertensive disorders in the mother is associated with paternal cardiovascular risk factors.

In a population-based study of 14,130 family units, data on parental cardiovascular risk factors (blood pressure, body mass index, waist circumference, nonfasting serum lipids and glucose) collected in the Norwegian Hunt Study (1995-1997) were linked to pregnancy data from the Medical Birth Registry of Norway (1967-1997). Multiple linear regression methods were used, and all analyses were adjusted for lifestyle factors likely to be shared by the parents.

There was no association between hypertensive disorders in pregnancy and paternal cardiovascular risk factors.

We found no evidence that the fathering of pregnancies complicated by hypertensive disorders in the mother is associated with an unfavorable paternal cardiovascular risk profile.

This paper aims to study if vaginal breech delivery is associated with increased risk for neonatal mortality (NNM) or cerebral palsy (CP) in Norway where vaginal delivery accounts for 1/3 of all breech deliveries.

Cohort study using information from the national Medical BirthRegister and Cerebral Palsy Register.

Births in Norway 1999-2009.

520 047 term-born singletons without congenital malformations.

NNM, CP and a composite outcome of these and death during birth.

Compared with cephalic births, breech births had substantially increased risk for NNM but not for CP. Vaginal delivery was planned for 7917 of 16?700 fetuses in breech, while 5561 actually delivered vaginally. Among these, NNM was 0.9 per 1000 compared with 0.3 per 1000 in vaginal cephalic delivery, and 0.8 per 1000 in those actually born by caesarean delivery (CD) in breech. Compared with planned cephalic delivery, planned vaginal delivery was associated with excess risk for NNM (OR 2.4; 95%?CI 1.2 to 4.9), while the OR associated with planned breech CD was 1.6 (95% CI 0.7 to 3.7). These risks were attenuated when NNM was substituted by the composite outcome. Vaginal breech delivery was not associated with excess risk for CP compared with vaginal cephalic delivery.

Vaginal breech delivery, regardless of whether planned or actual, and actual breech CD were associated with excess risk for NNM compared with vaginal cephalic delivery, but not with CP. The risk for NNM and CP in planned breech CD did not differ significantly from planned vaginal cephalic delivery. However, the absolute risk for these outcomes was low, and taking into consideration potential long-term adverse consequences of CD for the child and later deliveries, we therefore conclude that vaginal breech delivery may be recommended, provided competent obstetric care and strict criteria for selection to vaginal delivery.

Anxiety or depression symptoms may increase the risk of developing asthma, and their interaction with obesity is not known. We aimed to assess the association of anxiety or depression symptoms and the joint association of these symptoms and obesity with incident asthma.

We conducted a prospective cohort study of 23 599 adults who were 19-55 years old and free from asthma at baseline in the Norwegian Nord-Trøndelag Health Study. The Hospital Anxiety and Depression Scale was used to measure anxiety or depression symptoms. Obesity was defined as a body mass index=30.0 kg/m2. Incident asthma was self-reported new cases of asthma during the 11-year follow-up.

This study suggests that having anxiety or depression symptoms contributes to the development of asthma in adults. The risk of asthma may be further increased by the interaction between anxiety or depression symptoms and obesity.

Obesity is a risk factor for incident asthma in adults, and obesity is a major component of metabolic syndrome. This study aimed to explore the associations of metabolic syndrome and its components with the cumulative incidence of asthma in adults. We conducted a prospective cohort study of participants who were asthma-free at baseline (n = 23 191) in the Nord-Trøndelag Health Study from 1995 to 2008. Baseline metabolic syndrome was categorised using the definition of the Joint Interim Statement from several international organisations. Incident asthma was self-reported at follow-up, which averaged 11 years. Metabolic syndrome was a risk factor for incident asthma (adjusted OR 1.57, 95% CI 1.31-1.87). This association was consistent in sensitivity analyses using a stricter asthma definition (adjusted OR 1.42, 95% CI 1.13-1.79). Among the components of metabolic syndrome, two remained associated with incident asthma after mutual adjustment for the other metabolic components: high waist circumference (adjusted OR 1.62, 95% CI 1.36-1.94) and elevated glucose or diabetes (adjusted OR 1.43, 95% CI 1.01-2.04). Metabolic syndrome and two of its components (high waist circumference and elevated glucose or diabetes) were associated with an increased risk of incident asthma in adults.

Low birth weight is associated with increased risk of cardiovascular disease and type 2 diabetes in later life. The fetal insulin hypothesis suggests that shared genetic factors partly explain this association. If fetal genes predispose to both low birth weight and cardiovascular disease in adulthood, fathers of offspring with low birth weight should display an unfavorable profile of cardiovascular risk factors. To study this, the authors linked data on more than 14,000 parents, collected from the second Health Study of Nord Trøndelag County, Norway (HUNT 2, 1995-1997), to offspring data from the Norwegian Medical Birth Registry (1967-2005). Linear regression was used to study associations of offspring birth weight for gestational age with the parents' body mass index, waist circumference, blood pressure, glucose, and serum lipids. All analyses were adjusted for shared environment by means of the socioeconomic measures, lifestyle, and cardiovascular risk factors of the partner. The authors found that low offspring birth weight for gestational age was associated with increased paternal blood pressure, body mass index, waist circumference, and unfavorable levels of glucose and lipids. For mothers, associations similar to those for fathers were found for blood pressure, whereas associations in the opposite direction were found for glucose, lipids, and body mass index. The paternal findings strengthen the genetic hypothesis.